The present invention relates generally to an improved process for preparing combustible solid fuels, and more particularly to such a process for preparing a combustible solid fuel from grain residue which utilizes the in-situ cellulose to form a cohesive solid pellet. Live steam is utilized to cause the cellulose to form a binder material, with the pelletized product thereafter being useful as a fuel without increasing the ash or solid residue.
Fuel costs, and the cost of producing energy have increased substantially in the recent past. Alternate fuel sources are, of course, desirable, and particularly when an alternate fuel source is available from a recurring yearly source of supply. The cost of the product is relatively low, and it may be burned efficiently with the production of only modest or low amounts of solid residue.
Specifically, the process of the present invention provides an alternate source of combustible solid fuels, and utilizes grain residue which is normally discarded as a waste product. The grain residue is treated so as to form a pellet which is cohesive in form, and which may be burned either directly, or in combination with other solid or liquid fuels such as, for example, coal.
Grain residue is a waste product generated in the conversion of grain to edible products. The residue is produced in substantial quantities in mills, elevators, as well as in the agricultural fields. The process of the present invention utilizes these waste products to form a combustible solid fuel which is capable of being transported with modest protection from the elements, thereby retaining its useful form.
The benefits of utilization of grain residue as a fuel include the relatively low cost of the material, and particularly the low unit costs of BTU's. The grain residue is an item which is in recurring supply, with each annual crop providing a substantial quantity of this material. Since the material is capable of compaction and formation of pellets, the costs of storage are reduced, as are, of course, the costs of maintaining any inventory of this material. The material has a relatively high heat content, with the BTU's per pound being greater than that of either lignite coal or wood, while being less than that of anthracite coal or the like. The material burns with an extremely low sulfur content and produces very little solid waste in the form of ash. Another ultimate benefit of the use of this material is the preservation of irreplaceable natural resources.